That's good stuff. Would be better if you could work it into a combo. Off raw d2, you may be better off going with the guaranteed combo since resetting into b3/f3 won't add too much extra damage. If they're close to the corner it's pretty good because you can get the stage transition.
I think it'll be very useful against smart players, though. The average person won't even know that they got crossed up so there's no conditioning, but against a good player, that'll stick in their mind every time they eat a d2 (which should happen a lot now). Nice find, guys.